High data reliability, high speed of memory access lower power consumption and reduced scaling of chip size are features that are demanded from semiconductor memory. The reduced scaling of the chip size typically results in smaller feature sizes the various circuits of semiconductor memory. For example, in a memory array included in a semiconductor memory, memory cells, access line, sense line, sense amplifiers, as well as other circuits in the memory array are designed with smaller feature sizes. The circuits with smaller feature sizes may be more susceptible to process variations which cause variations in circuit performance from ideal circuit characteristics. Lower power consumption is often achieved by using lower internal voltages, such as using lower voltages for driving internal signals, for storing in the memory cells, etc. A consequence of the reduced scaling and reduction in power consumption is that the internal signals become challenging to detect and to transmit on signal lines.
With regards to memory cells and reading information stored in the memory cells, in particular in volatile memory, such as dynamic random access memory (DRAM), the continuous scaling of semiconductor memory and reduction in power consumption has a direct impact on the design and performance of the sense amplifiers that are used to read out the information stored in the memory cells. For example, the reduction of the memory cell dimensions and the increase of interconnection parasitic capacitance and resistance may result in difficulties in accurately reading stored information.